ASUS P4C800-E Deluxe - Lost ability to boot from SATA

[MajorKong]

I just set up a new machine today with the P4C800-E Deluxe, P4 3.0E, and a Serial ATA boot disk. I first set ip up with just the SATA disk on the ICHR5 SATA #1 channel, plus an optical drive as master on IDE #2.

I installed XP Pro without a hitch onto the SATA drive. Boots great - no problems.

Then I pulled a couple of Parallel ATA drives out of an older system and put them into the new system, placing them both on IDE channel #1. I also added a 2nd optical drive as a slave on IDE channel #2.

All of the drives are seen by the BIOS, but the BIOS only gives a choice to boot from the floppy drive or either of the master drives on the two parrallel ATA channels. Previously the choices had been between the floppy, the optical drive and the SATA drive.

What do I need to configure in the BIOS to re-enable the SATA drive to be a bootable?

WAS
---------
IDE #1 Master: (empty)
IDE #1 Slave: (empty)
IDE #2 Master: Optical drive
IDE #2 Slave: (empty)
SATA #1: SATA HDD (boot disk)
SATA #2: (empty)

NOW
---------
IDE #1 Master: PATA HDD
IDE #1 Slave: PATA HDD
IDE #2 Master: Optical drive
IDE #2 Slave: Optical drive
SATA #1: SATA HDD (boot disk)
SATA #2: (empty)